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Topic: Moving target - "What's a gateway?" (Read 4667 times)

[This isn't a LinuxMCE specific question, it's a networking question, but answers would apply to LinuxMCE.]

If one considers a gateway (an aspect of LinuxMCE) as something the rest of the network goes through, and as a logical spot for provisioning of network services ... (e.g. firewall between inside and outside networks, and ntp)

"What's a gateway?" (What all is it composed of?)

It's a moving target. e.g. Not too many years ago asterisk wasn't something that immediately came to mind as something that should be on a gateway. As internet life evolves, so will the gateway.

When I have looked around the web, gateway 'aspects' are strewn all about the 'documentation.' Some aspects are in server provisioning, other aspects are in desktop provisioning (e.g. nfs/samba), other aspects are small topics unto themselves. I can't recall coming across a 'networking' 'category' of documentation / one-stop shopping.

I haven't come across any good links as to "What's a gateway?" / "What all a gateway does?"

- a simple checklist would be a good start, e.g. It has this and this and that and that.

Anyone with any good links / references / etc.?

Thanks.

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Technically speaking, a gateway operates at the application layer (Layer 7) and converts between high-level protocols. So a device that converts between VoIP and, say ISDN would be a gateway (e.g. an AudioCodes Mediant). Similarly, something that allows a Lunux system to access Windoze shares (CIFS) could be considered to be a gateway (i.e. SAMBA).

The confusion comes from terminology revolving around IP. In this case, we have a parameter called the default gateway, which isn't a gateway at all, but a router operating at the network layer (Layer 3).

Please note, I'm talking from a purist, networking perspective (as you asked!). As always, the original meanings and defininitions have become distorted over time as the technology and applications evolve. The result is a plethora of interpretations and differing uses

Technically speaking, a gateway operates at the application layer (Layer 7) and converts between high-level protocols.

I do not second that. Are you maybe talking about an "application level gateway"? The term "gateway" alone is absolutely no indication for layer 7 operation. The OSI definition: "A Gateway operates at the Transport Layer and above. Typically translating each source layer protocol into the appropriate destination layer protocol."

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The confusion comes from terminology revolving around IP. In this case, we have a parameter called the default gateway, which isn't a gateway at all, but a router operating at the network layer (Layer 3).

The "default gateway" is used in TCP/IP "speak" as abbrevation for "default gateway router". So I'd say it is a gateway. E.g. look at what the "G" in IGP or BGP stands for :-)

Although: Default gateway is perfectly correct. It is the device through which the internal network (ethernet) passes to get on to the outside medium (usually providers modem).

Let's use that sense of gateway, and add the network services one wants in a home / small network, in essence, all the goodness one would want in a 'home server' so that all the other machines are mere clients. Which is also to say, I could sit down at any one of them, or bring in a new one, or remove one without any adverse effects to network functionality.

That's not to say you can't have, or don't want, redundancy (e.g. on-site backups), but let's just get the list of 'things' first.

Even better, if anyone has a link that covers this off. e.g. Checklist of services.

In the meantime, dhcp, ntp, named, proxy, net nanny for those who need it, dns, asterisk, torrent (in the sense of port forwarding), firewall, and ???

And, oh yeah, LinuxMCE core! (-:

What all makes up an ubergateway / home server?

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This is a discussion in a forum. Perhaps out of it will be a checklist of feature requests, but we're not there yet.

lmce must become as ubiquitous as the browser.

If it must be a gateway, be a gateway. What a gateway is, seems to be a moving target.

Nobody has said low power. IIRC, the wiki / docs / links / whatever seem to indicate the core cannot have too much power. I can certainly see how lmce scales up and down - be it the DVD appliance, or the base CD install, and/or with software added.

All I have asked here is if anyone has any links, or ideas, as to what a 'ubber mega super gatway' would be composed of.

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Simple answer: Define 'need.' Or is lmce to not only be an ubergateway, but be able to read your mind as well.

1 step further: Do you know what you need?

Proper answer: All the appropriate things a gateway / network services / home server / home control device needs to run, in a modern (evolving), industry standard / recognized / best practices manner, to satisfy the customer's needs and requirements, whether they understand all those best practices or not (i.e. to know they need something).

Problem 1: What the heck is 'that', then?Problem 2: Who is your customer?

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I have noticed that some of the regular posters are once again getting short, to the point of being rude. You guys need to remember that this is a public forum which anybody can join and post on. That anybody will include all levels of experience and many of their posts will be irritating. New users will post questions that have already been asked (yes, there is a search bar!) or in the wrong place. The more regular and experienced users need to at worst simply ignore such posts, or at best redirect the OP to the correct place (whilse swearing quietly under their breath!!!) Simply being rude or, even worse, closing a thread does not help the karma of the forums at all. There were 2 threads recently started by lmce3000 on this very subject:

Yes, it perhaps shouldn't be in this forum, but why not gently re-direct the user to the correct forum?

Hari, I have had run-ins with you before on this subject. I have asked questions and had you (I assume it was you as you responded in the thread) simply lock the posting, preventing others from responding. I was accused of not doing my own research, yet in my posts I pointed out that the wiki was giving conflicting messages and that I was seeking clarification.

Please, everyone, can we try to remain friends and avoid sarcastic or abusive comments? It may be that thinks are said in jest, but it is easy to mis-interpret stuff that is written and offence caused that was not intended.

I know everyone here is voluntary and you all give of your time very generously. This is appreciated and as soon as I am up to speed, I will return my experience to the pool.

Moving back to the OP and question...

What I stated in message #2 I stand by. Yes, a gateway is Layer 4+, but the point being that the OSI model (which is NOT the IP model) has a definate split between Layer 3 and Layer 4. They are often referred to as the "lower layers" and "upper layers" respectively. When the archetects of IP (which has become virtually the only protocol out there now) started naming things, they used the term "gateway" incorrectly. I agree that your default gateway MAY have to act as a proper gateway if a WAN is involved, but this is by no means a requirement. In many applications, a router (=default gateway) is between two ethernet segments. It is this that leads to a lot of the confusion around today. I should know, I teach this stuff for a living and it causes endless confusion when in one breath you use the term "gateway" to mean router and in the next to mean a device to convert ISDN to VoIP!!!! In a home network, based on LMCE, you have this very situation. Your core has two NICs. It routes traffic between the public and private networks. Both are ethernet. When you look at your client's network settings, it has the "Default Gateway" set to be the core, which is acting as a router NOT a gateway. To start justifying it by saying things like

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The "default gateway" is used in TCP/IP "speak" as abbrevation for "default gateway router".

is to fall into the Micro$oft trap of redefining standards and terminology and then claiming due to sheer weight of numbers and market penetration that your interpretation is the correct and only one.

I'm sorry, but if we are to be correct, and answer the OP's question, we need to draw this distiction. Routers translate between networks (Layer 3) Gateways between protocols (Layer 4+). As Hari correctly states, the OSI definition (NOT the IP one!) is

Yes, it perhaps shouldn't be in this forum, but why not gently re-direct the user to the correct forum?

I've gently referred the user to feature requests.

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Hari, I have had run-ins with you before on this subject. I have asked questions and had you (I assume it was you as you responded in the thread) simply lock the posting, preventing others from responding. I was accused of not doing my own research, yet in my posts I pointed out that the wiki was giving conflicting messages and that I was seeking clarification.

was that you who opened 4 topics for FAQ? I think thats rude in a forum.

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When the archetects of IP (which has become virtually the only protocol out there now) started naming things, they used the term "gateway" incorrectly.

incorrectly from which point of view? ISO/OSI is not the only way to name things..

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When you look at your client's network settings, it has the "Default Gateway" set to be the core, which is acting as a router NOT a gateway. To start justifying it by saying things like

Quote

The "default gateway" is used in TCP/IP "speak" as abbrevation for "default gateway router".

is to fall into the Micro$oft trap of redefining standards and terminology and then claiming due to sheer weight of numbers and market penetration that your interpretation is the correct and only one.

and what trapped you to think the OSI definition is the only valid one? I think i stressed the fact that definitions are all about the context.

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I'm sorry, but if we are to be correct, and answer the OP's question, we need to draw this distiction. Routers translate between networks (Layer 3) Gateways between protocols (Layer 4+). As Hari correctly states, the OSI definition (NOT the IP one!) is

sorry, read the OP's question again. The only answer is "go to feature requests", as he is surely not interested in networking theory. And I knew where his questioning will end after reading the second post. Hey, he does not even know which features the devs _must_ implement for him, just let it be "ubber".